For most folks sedation is unnecessary for pouchoscopy. Some folks have particular reasons for preferring or requiring it. I've never considered sedation.
Since we no longer have sigmoid colons, we can't really have a flexible sigmoidoscopy ("flex sig") - the procedure is correctly called "pouchoscopy." The term "flex sig" sometimes still gets used for several reasons: 1) the instrument used is a flexible sigmodoscope (also called a "flex sig"), 2) the staff knows what a flex sig is, but may not know what a pouchoscopy is, and 3) the billing code used is the one for flexible sigmoidoscopy.
Beware an unnecessarily intense prep that might be appropriate for a true flex sig, but simply isn't needed for a pouchoscopy. The pouch can easily be cleaned out with an enema.